Using the dataset of child weights above, we can find the min and max. The min is simply the lowest observation, while the max is the highest observation. Obviously, it is easiest to determine the min and max if the data are ordered from lowest to highest. So for our data, the min is 13 and the max is 110.

Using the Min and Max

Finding the min and max helps us understand the total span of our data. There are a variety of reasons you might do this depending on the study. It’s usually something that is nice to know and helps you feel more familiar with your data. Or you can do a min and max to help you identify something wrong.

For instance, maybe for our study of childhood weight, we really only want to focus on children over the age of two years old. By identifying the min of 13 pounds, we may be concerned that we have unknowingly gotten an infant in our study. We would then want to further investigate how this occurred, if there are other infants in our dataset, and what should be done with these data as we proceed with the data analyses.

Range

Sometimes it is also useful to use the min and max to calculate the range of a dataset. The range is a numerical indication of the span of our data. To calculate a range, simply subtract the min (13) from the max (110). The range for this dataset is 97.

The range is another example of something that is nice to know, but isn’t all that useful unless we are comparing it with something else.